Confession time here: FH and I talk on the phone all the time while one of us (mostly him) is in the restroom. I would never ever do that in a public place, or to anyone but him or close family. For FH, he is a very active person, and that is one time in the day that he stops. So, he calls me then. I never hear anything. I guess I have family that talks on the phone for a long time. So, I just mute it when I am making noise, and unmute when I need to say "A Ha".